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Another physics layperson question here: Can this technique of studying a past state reversal apply to compromising one-way hash functions in some manner?
by otoburb 8y ago
Another physics layperson question here: Can this technique of studying a past state reversal apply to compromising one-way hash functions in some manner?
- drinane 8y agoYes that is one of the reasons for big gubment interest in quantum machines, but allegedly those algorithms require control of millions of qubits and right now the highest qubit machine publicly disclosed is 50 I think.
- krastanov 8y agoNo! Contrary to what the sibling comment says, there are plenty of one-way hash functions that are resistant to quantum computers. Two comments though: 1. This particular work is explicitly relying on the fact that many quantum operations (including the type of time evolution they are considering) are a one-to-one map (not the one-to-many "irreversible" hash functions). Hence this work is explicitly not applicable. 2. Quantum computers do break some form of public key encryption, but this is a solved problem, as there are many other public key encryption protocols that are can not be broken by a quantum computer. Quantum computers do provide modest speedup in all types of brute force searches, like breaking symmetric encryption, but this is trivial to defend against by using a slightly bigger encryption key.